Buoyant screw-propeller



(No Model.)

G. S. BURR. BUOYANT SCREW PROPELLER. No. 333,445. v Patented Dec. 29,1885.

I 172mm), 1;. W v 9%. (7? [3m ar/ zzy UNITED STATES PATENT OFFICE.

GEORGE S. BURR, OF EVERGREEN, COLORADO, ASSIGNOR OF ONE-HALF TO JAMESBILLINGSLEY, OF BALTIMORE, MARYLAND.

BUOYANT SCREW-PROPELLER.

SPECIFICATION forming part of Letters Patent No. 333,445, dated December29, 1885.

Application filed October 15, 1885. Serial No. 179,921. (No model.)

To all whom it may concern: the screw-propeller will be revolved, and

Be it known that I, GEORGE S. BURR, a thereby the craft will be moved.Any suitcitizen of the United States, residing at Everable contrivancemay be employed in the boat green, in the county of Jefferson and Stateof to impart motion to the shaft L. In the pres- (Jolorado, haveinvented certain new and useent instance a crank. m, is fixed to theshaft. ful Improvements in Buoyant Screw-Propel- It may be driven bysteam or other power. lers, of which the following is a specification.Arudder, N, is rigged at the stern and extends My invention relates toan improvement in down the rear upright end of the false-keel 5 boats,the object being to provide a boat with bar, and a tiller, 0, is fixedto the rudder-post,

IO ascrew-prope1ler,which will also serve to buoy as usual. It will beseen that for a light boat up or sustain the boat. the hollow cylindermay serve to sustain it The invention is illustrated in the accomwhenunloaded, as shown in Fig. 3, entirely panying drawings, in which Figurel is a side above the water. The relative size and weight L view of theimproved boat. Fig. 2 is a top of hollow cylinder and boat may be suchas,

1 view. Fig. 3 is an end view showing the powhen loaded, to let theboatset lightly on the sition of the boat in the water when unloaded.surface of the water without displacing much Fig. Aisa cross-section ofthe screw-propeller. water. It is obvious two hollow cylinders The boatA may be of any desired shape or maybe thus provided with spiralflanges, and 6 construction. For the purpose of illustration the twoplaced side by side and the boat 20 the ordinary shape is here shown. Ahollow wholly sustained above them. Properly contight cylinder, B,hasaspi-ral flange, 0, around structed on this plan, a boat may be movedit, which serves as a screw-propeller. The with great rapidity. 1cylinder being light will float and gives buoy- Instead of a hollowcylinder the cylinder ancy to the boat. The cylinder inayhave any may bemade solid, but of some very light 25 desired shape at the ends-rounded,square, buoyant material, like cork, so as to have the ortapering-somewhat cone'shaped, as shown desired buoyant properties. at d1n Fig. 1. The spiral flange may be se Having described my invention, Iclaim and cured to the cylinder in any convenient or desiretosecurebyLettersPatentof the United approved manner. In the present instanceStates- 0 one flange continues spirally around it from 1. A boat havinga false-keel bar, G, in end to end; but two flanges may be used, ifcombination with a buoyant cylinder having desired. At each end thecylinder has a joura spiral flange and mounted between the said nal, e,which sets in a bearing, f, on a metal false-keel bar and boat, as setforth. keel-frame, G. This keel-frame G is an iron 2. A boat havingin'conibination a body, a

5 bar, whose upright ends h support the boat, false-keel bar dependingbelow the body, a while the lower longitudinal part between the buoyantcylinder provided with a spiral flange said two upright ends is a kindof false keel, and mounted between the body and false-keel P and servesas a ballast to prevent the craft bar, and driving mechanism,substantially as from careening. The screw-propeller O is described,connecting the boat-body with the 0 thus between the lower bar and theboat, and buoyant cylinder, as set forth.

turns in its bearing f. At the stern end the In testimony whereof Iaffix my signature in journal 6 has a spur-gvheel, t, and) 1a shaltt, L,presence of two witnesses.

asses through the oat, a suita e pac ing, 3 in the boat-bottom beingprovided to pre- GEORGE BURR' 5 vent leakage, and a spur-wheel, Z, onthe shaft Witnesses:

engages with the spur-wheel i on the screw- S. E. MASSON, propeller. Byturning the shaft L in the boat D. L. N ESTER.

